Compatible Cat Water Fountain: Replacement filters are compatible with PETLIBRO Dockstream Cat Water Fountain models PLWF005, PLWF115, and PLWF105. In the Box: Includes 8 filters and 8 sponges. Usage Time: Lasts up to 4 months with regular use; for optimal performance, replace every 2 weeks. All-Day Purified Water: Effectively removes hair, dirt, and impurities to keep water fresh and clean. Tips: Soak the filter in water for 5 minutes before first use. For best results, use official replacement filters. Vertical Filtration System: Utilizes multi-layer filtration to purify water and enhance taste: 1. Activated carbon reduces bad odors. 2. Ion exchange resin helps remove heavy metal ions and softens water. 3. Non-woven fabric layer captures cat hair and debris. 4. Built-in pump sponge traps particles to prevent clogging and protect the pump.